Download Bone Marrow Failure

Bone Marrow Failure
Review Course 2013
Akiko Shimamura
1. An 8-year-old boy presents with a platelet count of 84,000/mm3 and macrocytosis
(MCV 101). His reticulocyte count is 1%. His physical exam is unremarkable. Serum
chemistries including LDH, bilirubin, and uric acid are normal. The bone marrow
aspirate shows decreased megakaryocytes and reduced cellularity (45%). The most
important test to do next is:
A. Direct and indirect antiglobulin testing
B. Anti-platelet antibody testing
C. Thrombopoietin levels
*D. Cytogenetics studies of the bone marrow
Answer: D
Explanation: Peripheral cytopenias with macrocytosis a hypocellular marrow may be
caused by aplastic anemia (moderate in this case), inherited marrow failure, or
myelodysplastic syndrome (MDS). Clonal cytogenetic abnormalities may be seen with
inherited marrow failure syndromes or MDS. Hemolytic anemias are typically associated
with elevated reticulocyte counts, normal or increased marrow cellularity, and sometimes
an elevated LDH and indirect bilirubin levels. Anti-platelet antibody testing is currently
neither sensitive nor specific for the diagnosis of ITP. The decreased marrow
megakaryocytes are also atypical for ITP. Thrombopoietin levels would not distinguish
between aplastic anemia, inherited marrow failure or MDS.
2. A mother with two sons and one daughter brings her youngest son (10 years old) to
you for consultation regarding his diagnosis of severe aplastic anemia. He is transfusiondependent for red cells and platelets and his ANC is 300. Workup for an underlying
inherited marrow failure syndrome is negative. You proceed to do the following:
A. Initiate treatment with ATG and cyclosporine
*B. Send HLA typing on all full siblings and consider HLA testing of parents
C. Initiate G-CSF therapy
D. Observe closely for spontaneous improvement.
Answer: B
Explanation: In children the treatment of choice for severe aplastic anemia is an HLAmatched sibling stem cell transplant. Testing of parents allows better tracking of alleles in
families and parents may have a small chance of being suitable match so routine parental
testing is done in some centers. Hematopoietic stem cell transplant is curative for aplastic
anemia. Blood counts often remain abnormal, albeit improved, after ATG and cyclosporine
and there is an ongoing risk of relapse. Short-term survival with HLA-matched sibling
transplant is comparable to that achieved with immune therapy. Long-term outcomes are
better with an incidence of late malignancy lower than that of the emergence of clonal
disease (AML, MDS, PNH) for transplant compared to immune therapy. Randomized trials
with G-CSF did not show improvement in outcomes for aplastic anemia. Prolonged
observation of severe aplastic anemia increases the risks of complications such as
allosensitization or infections.
3. A 16-year-old boy presents with a platelet count of 35 X 109/L, a hemoglobin of 7 g/dl, and
a neutrophil count of 450/μL. MCV is 108 fL. Reticulocyte count is 0.5% (corrected for
hematocrit). His bone marrow biopsy is notable for a cellularity of 25%. His physical exam is
otherwise normal. His mother also reports mild cytopenias but never required medical
intervention. She has dyed her hair ever since it turned grey at the age of 14. His maternal
grandfather died of pulmonary fibrosis at the age of 50. The patient’s 40-year-old maternal
aunt was recently diagnosed with liver cirrhosis and osteopenia. The following test is most
likely to be diagnostic:
A. Chromosomal breakage testing with DEB or MMC
B. Flow cytometry for GPI (glycosylphosphatidyl inositol)-anchored cell surface
markers
*C. Telomere length measurements
D. Bone marrow cytogenetics
Answer: C
Explanation: This history of familial anomalies is suggestive of a familial marrow failure
syndrome. Early graying, idiopathic pulmonary fibrosis, liver abnormalities, and osteopenia
are all features associated with dyskeratosis congenita. To date, all the genes associated with
dyskeratosis congenita involve either components of telomerase or affect telomere length
through the shelterin complex. The familial pattern here suggests an autosomal-dominant
pattern, while Fanconi anemia is autosomal recessive or X-linked and does not involve this
constellation of findings. Bone marrow cytogenetic studies are important to guide medical
management but do not establish which inherited marrow failure syndrome might be present.
Loss of GPI-anchored cell surface markers is a hallmark of PNH.
4. A 12-year-old girl with severe aplastic anemia and a negative workup for inherited marrow
failure syndromes was treated with antithymocyte globulin (ATG) and cyclosporine. One
week following treatment with ATG, she developed a fever to 38.6 ºC and an erythematous
maculopapular serpiginous rash along the borders of her palms and soles. She also
complained of pain in her knees, hips, and back. Blood cultures are negative. The most likely
etiology for her symptoms is:
A. Reaction to antibiotics
*B. Serum sickness
C. Viral infection
D. Graft versus host disease
Answer: B
Explanation: Symptoms of serum sickness are caused by the formation and deposition of
immune complexes and complement fixation.The typical time frame for serum sickness
following ATG treatment is 5-11 days following the first ATG dose. The pattern of
distribution for this rash is classic for a serum sickness rash. Symptoms may also include
fever, myalgias, and arthralgias. Gastrointestinal and neurologic symptoms may also occur.
Renal dysfunction may be seen but is typically transient. Workup to rule out infectious
etiologies should be undertaken promptly since the patient is immunocompromised at this
stage. Graft versus host disease may result from the transfusion of unirradiated blood
products into an immunocompromised host. Reduced cellular immunity is not a typical
feature of acquired aplastic anemia prior to treatment.
5. You are seeing a 10-year-old boy with severe aplastic anemia. On exam, he has no
dysmorphic features and is at the 50th percentile for height and weight. His family history is
notable for a sister who at the age of 12 also developed aplastic anemia unresponsive to ATG
and cyclosporine. This sister unfortunately died early in the course of an unrelated donor
hematopoietic stem cell transplant, which was complicated by severe mucositis and
transplant-related organ toxicities. There are no other siblings. A cousin died of AML at the
age of 5. You send a blood sample to test for Fanconi anemia and it is negative (no increased
chromosomal breaks in response to DEB or MMC). The most important test to do next is:
A. Initiate a matched unrelated donor transplant using a standard conditioning
regimen.
B. Send a bone marrow aspirate for Fanconi anemia testing.
* C. Send a skin sample for Fanconi anemia testing.
D. Administer ATG and cyclosporine.
Answer: C
Explanation: A family history of a sibling with aplastic anemia and a cousin with AML
raises the possibility of an inherited marrow failure syndrome even in the absence of other
clinical stigmata. The high transplant-related toxicity experienced by the sibling is suggestive
of a syndrome such as Fanconi anemia. A reduced intensity transplant conditioning regimen
would be indicated for a patient with Fanconi anemia. Blood tests for Fanconi anemia may be
negative if the lymphocytes have reverted to wild type (somatic mosaicism). The gold
standard to establish the diagnosis of Fanconi anemia in this situation is to test skin
fibroblasts for Fanconi anemia. There is currently no advantage to testing the bone marrow
aspirate for chromosomal breakage since somatic mosaicism has also been reported in the
hematopoietic lineages and chromosomal breakage assays have not been standardized for
marrow samples. Patients with Fanconi anemia typically fail to respond to ATG and
cyclosporine therapy for aplastic anemia.
6. An 8-year-old boy with Fanconi anemia who recently moved from another state presents to
you for the first time. His family reports that he has been on “some sort of medication” to
treat his low blood counts. His kidney function has been normal. A recent liver ultrasound
obtained just prior to his move revealed a new liver adenoma. The medication to treat his low
blood counts was most likely:
A. G-CSF
B. GM-CSF
*C. Oxymetholone
D. Erythropoietin
Answer: C
Explanation: Cytopenias, particularly anemia, improve with oxymetholone therapy in over
50% of Fanconi anemia patients. While liver adenomas may develop spontaneously in
Fanconi anemia patients, the risk of developing a liver adenoma or liver tumors is increased
with oxymetholone. Regular screening with liver function tests and liver ultrasounds to
monitor hepatic toxicity are recommended for Fanconi anemia patients receiving
oxymetholone. Androgen-associated liver adenomas may resolve after androgens are
discontinued, but some may persist even years after androgens are stopped. While
neutropenia in Fanconi anemia patients may respond to treatment with G-CSF or GM-CSF,
neither of these treatments are associated with an increased risk of liver adenomas.
Erythropoietin is generally reserved for Fanconi anemia patients who have low erythropoietin
levels.
7. A 2-year-old boy presents with failure to thrive and neutropenia. His parents report
frequent, runny, malodorous stools. His exam is otherwise unremarkable. His blood counts
are notable for a wbc of 5,000/μL, ANC 500/mm3, hemoglobin of 11g/dl, platelet count of
200 x 109/L, MCV 110 fL with normal B12 and folate levels. His prothombin time (PT) is
slightly prolonged, but PTT and fibrinogen are normal. Liver enzyme levels and bilirubin
levels are normal. Sweat test for cystic fibrosis and workup for celiac disease is negative. No
intestinal pathology is noted by upper or lower endoscopy. Mutations in which of the
following genes might account this constellation of symptoms?
A. ELA2
B. HAX1
*C. SBDS
D. RPS19
Answer: C
Explanation: Failure to thrive, steatorrhea, and the elevated PT suggestive of vitamin K
deficiency are consistent with fat malabsorption. The combination of exocrine pancreatic
insufficiency and otherwise idiopathic neutropenia are diagnostic of Shwachman-Diamond
syndrome, which is associated with mutations in the SBDS gene. ELA2 mutations are
associated with severe congenital neutropenia (SCN) or cyclic neutropenia (CN). HAX1
mutations are also associated with SCN. Exocrine pancreatic insufficiency is not
characteristic of either SCN or CN. RPS19 mutations are associated with Diamond-Blackfan
anemia, which is characterized by red cell aplasia.
8. An 18-year-old boy presents with AML. He had severe neutropenia first noted in infancy
and had a history of recurrent bacterial infections and oral aphthous ulcers. The neutrophil
counts rose to normal and the infections resolved after the initiation of G-CSF. Analysis of
the leukemic clone revealed an acquired mutation in the cytoplasmic domain of the G-CSF
receptor. A mutation in the following gene might be found in this patient:
*A. ELA2
B. RPS19
C. c-Mpl
D. FANCA
Answer: A
Explanation: ELA2 mutations are associated with severe congenital neutropenia (SCN) or
cyclic neutropenia (CN).Mutations in the G-CSF receptor frequently arise in patients with
severe congenital neutropenia. The mutations typically result in constitutive activation of the
G-CSF receptor. The clinical significance of these mutations is currently unclear since some
mutant G-CSF clones progress to leukemia while others remain stable for many years. RPS19
mutations are associated with Diamond-Blackfan anemia. C-Mpl mutations are associated
with congenital amegakaryocytic thrombocytopenia. FANCA mutations cause Fanconi
anemia subtype A.
9. A 19-year-old boy presents with a hemoglobin of 7g/dL, wbc of 900/μL, ANC 10/μL,
platelet count 10 X 109/L. The reticulocyte counts is low. The MCV is 115fL with normal
B12 and folate levels. At the age of 5 he had been treated with ATG and cyclosporine for
idiopathic aplastic anemia since he has no matched siblings. He had a good initial response to
treatment with normalization of his blood counts until recently. The most important next step
is:
A. Start cyclosporine
B. Start ATG and cyclosporine
C. Refer him for a matched unrelated donor transplant
*D. Perform a bone marrow aspirate and biopsy with cytogenetics
Answer: D
Explanation: Relapse of aplastic anemia following treatment with ATG and cyclosporine is
common (currently estimated at around 30%). Patients with aplastic anemia are at increased
risk for developing clonal cytogenetic abnormalities, including monosomy 7, as well as at
increased risk for leukemic transformation. Thus, a bone marrow aspirate and biopsy with
cytogenetics would be the next step to evaluate the etiology of his cytopenias in order to
guide treatment decisions.
10. This is your first meeting with a 19-year-old boy who presents with a 5-year history of
mild but stable thrombocytopenia (platelet count ranging between 105-120 x 109/L). His cbc
shows a wbc of 7,000/μL, hemoglobin of 13 g/dL, platelet count of 115 X 109/L, MCV of
110fL, and a neutrophil count of 2,500/μL. B12 and folate levels are normal. His father, who
does not smoke or drink, developed oral squamous cell carcinoma at the age of 25. The exam
is notable for leukoplakia. Which of the following tests are most likely to be helpful in
establishing a diagnosis?
*A. Telomere length analysis
B. c-mpl sequence analysis
C. RPS19 genetic testing
D. Normal platelet variant
Answer: A
Explanation: Longstanding cytopenias with idiopathic macrocytosis are frequent features of
inherited marrow failure syndromes. Leukoplakia with an increased risk of squamous cell
carcinoma is associated with dyskeratosis congenita and the family history is consistent with
an autosomal dominant pattern of inheritance. The inheritance patterns of dyskeratosis
congenita vary, depending on the gene, and may follow autosomal dominant, autosomal
recessive and X-linked modes. Fanconi anemia is associated with increased risk of
squamous cell carcinoma but is a recessive genetic disorder. Suspicious lesions should be
biopsied promptly. C-mpl mutations are associated with congenital amegakaryocytic
thrombocytopenia and RPS19 mutations are associated with Diamond-Blackfan anemia.
Neither CAMT nor DBA are associated with an increased risk of leukoplakia or squamous
cell carcinomas.
11. A 15 month old boy is referred to you for neutropenia, malabsorption, and severe
acidosis. The bone marrow examination shows vacuolated erythroid precursors and ringed
sideroblasts. Cytogenetics were normal. The most important test to send is:
*A. Mitochondrial DNA sequencing
B. SBDS genetic testing
C. MMC/DEB chromosomal breakage study
D. Telomere length assay
Answer: A
Explanation: This is the classical morphologic finding in the bone marrow of patients with
Pearson syndrome resulting from a mitochondrial DNA deletion. Shwachman-Diamond
syndrome is caused by mutations in the SBDS gene. Although Shwachman-Diamond
syndrome and Pearson syndrome both present with marrow failure and exocrine pancreatic
dysfunction, Shwachman-Diamond syndrome lacks these marrow findings. MMC/DEB
chromosomal breakage study is the diagnostic test for Fanconi anemia. Very short telomere
lengths are associated with dyskeratosis congenita.
12. A 6 year old boy is referred for evaluation of severe pancytopenia and marrow
hypoplasia. On exam, you note short stature, three café au lait spots, a scar from surgical
correction of a congenital thumb anomaly. The most important test to send next is:
A. Erythrocyte adenosine deaminase activity (eADA) determination
B. Flow cytometric evaluation of CD55/CD59
*C. Mitomycin D/DEB chromosomal breakage assay
D. Mitochondrial DNA deletion analysis
E. Testing for neurofibromatosis
Answer: C
Explanation: This is a classic presentation of Fanconi anemia, which is associated with
increased chromosomal breakage in response to MMC or DEB. Elevated eADA may be seen
with Diamond-Blackfan anemia, which typically presents with pure red cell aplasia. Absence
of CD55/CD59 is seen with PNH. Mitochondrial DNA deletion is associated with Pearson
syndrome. Café au lait spots are seen in neurofibromatosis, but marrow failure and thumb
abnormalities are not typical of this disorder.
14. You are called to the newborn nursery to see a baby with cutaneous and mucosal
bleeding. The platelet count is 20,000/mm3. The other blood counts are normal. Labor and
delivery were uncomplicated and maternal platelet counts are normal. No maternal
medications. There are no signs of infection. On exam, the baby’s arms appear abnormal.
Your differential diagnosis includes the following:
A. Acquired aplastic anemia
B. Shwachman-Diamond syndrome
*C. Thrombocytopenia absent radii syndrome (TAR).
D. Diamond-Blackfan anemia
Answer: C
Explanation: Both FA and TAR may present with radial anomalies and low platelets in
infancy. Shwachman-Diamond syndrome may present with cytopenias but radial ray
anormalies have not been commonly reported. Diamond-Blackfan anemia presents with red
cell aplasia. Acquired aplastic anemia is not typically associated with congenital anomalies
15. A 5 year old girl with a previously normal cbc now presents in your office with a
hemoglobin of 8.5 g/dL, corrected reticulocyte count of 0.1%, normal red cell MCV, the
remainder of her cbc was normal. Vital signs and physical exam was normal. Bilirubin, LDH,
BUN, creatinine and urinalysis are normal. Direct and indirect antiglobulin tests are negative.
Workup for infection, including parvovirus, is negative. She has no evidence for ongoing
blood loss, no occult blood in her stools. The most appropriate next step is:
A. Send red cell adenosine deaminase
*B. Observe closely
C. Initiate a red cell transfusion
D. Administer erythropoietin
Answer: B.
Explanation: Diamond-Blackfan anemia (DBA), which is often associated with an elevated
erythrocyte adenosine deaminase level, typically presents in infancy with macrocytic red cell
aplasia. Transient erythroblastopenia typically presents at an older age than DBA and the
MCV is typically normal. In an asymptomatic patient, transfusion may be deferred at this
hemoglobin level. Erythropoietin levels are typically already high with red cell aplasia.
2015
Bone Marrow Failure
Zora R. Rogers, MD
1. An 8-year-old boy presents with a platelet count of 84,000/mm3, hemoglobin 10.4
g/dl, MCV 101, reticulocytes 1%, and white blood cell (WBC) count of 1,100/mm3
with 25% neutrophils. His physical exam is unremarkable. Serum chemistries,
including LDH, bilirubin, and uric acid, are normal. The bone marrow aspirate shows
a cellularity of 40% with decreased megakaryocytes. The most important test to
perform to establish a diagnosis is
A. Antiplatelet antibody test
B. Bone marrow cytogenetics
C. Direct antiglobulin test
D. Erythropoietin level
E. Thrombopoietin level
2. A 10-year-old male with severe aplastic anemia (SAA) comes to see you along with
his parents and two sisters. He is transfusion-dependent for red cells and platelets
and his absolute neutrophil count (ANC) is 300/uL. Workup for Fanconi anemia and
infectious causes of the marrow failure are negative. What do you recommend as
the next step in management of this patient?
A. G-CSF therapy at the lowest dose and frequency possible
B. Human leukocyte antigen (HLA) typing on patient and all full siblings
C. Immunosuppressive therapy with ATG and cyclosporine
D. Observation for spontaneous improvement
E. Oral androgens treatment
3. A 16-year-old boy presents with a hemoglobin of 7.0 g/dl, mean corpuscular volume
(MCV) 108 fL, reticulocyte count 0.5%, ANC of 450/μL, and platelet count of
35,000/mm3. His bone marrow biopsy has a cellularity of 25%. His physical exam is
otherwise normal. His mother also reports mild pancytopenia but never required
medical intervention. She has dyed her hair ever since it turned grey at the age of
14. His maternal grandfather died of pulmonary fibrosis at the age of 50. The
patient’s 40-year-old maternal aunt was recently diagnosed with liver cirrhosis and
osteopenia. Which of the following tests is most likely to be diagnostic of this
familial disorder?
A. Bone marrow cytogenetics
B. Chromosomal breakage testing with DEB or MMC
C. Flow cytometry for GPI (glycosylphosphatidyl inositol) anchored cell surface
markers
D. Serum trypsinogen and fecal elastase
E. Telomere length measurements
4. A 12-year-old girl with SAA was treated with ATG and cyclosporine. One week
following completion of treatment with ATG, she developed a fever to 38.6 °C and
an erythematous maculopapular serpiginous rash along the borders of her palms
and soles. She also complained of pain in her knees, hips, and back. Blood cultures
are negative. The most likely cause of her symptoms is
A. Graft-versus-host disease
B. Reaction to antibiotics
C. Serum sickness
D. Transfusion reaction
E. Viral infection
5. You are seeing a 10-year-old boy with SAA. On exam, he has no dysmorphic features
and is at the 50th percentile for height and weight. Family history is notable for a
sister with aplastic anemia unresponsive to ATG and cyclosporine who died early in
the course of an unrelated donor hematopoietic stem cell transplant complicated by
severe mucositis and transplant-related organ toxicities. There are no other siblings.
A cousin died of AML at the age of 5. Testing of a peripheral blood sample for
Fanconi anemia is negative (no increased chromosomal breaks in response to DEB or
MMC). Which of the following is the most important next step?
A. Administer ATG and cyclosporine.
B. Search for a donor for matched unrelated transplant.
C. Send a bone marrow aspirate for Fanconi anemia testing.
D. Send a skin fibroblast culture for Fanconi anemia testing.
E. Start oral therapy with oxymethalone.
6. An 8-year-old boy with Fanconi anemia who recently moved from another state
presents to you for the first time. His family reports that he has been on “some sort
of medication” to treat his low blood counts. His kidney function has been normal. A
recent liver ultrasound obtained just prior to his move revealed a new liver
adenoma. The medication to treat his low blood counts was most likely
A. Danazol
B. Erythropoietin
C. G-CSF
D. GM-CSF
E. Oxymetholone
7. A 2-year-old boy presents with failure to thrive and neutropenia. His parents report
frequent, runny, malodorous stools. His exam is otherwise unremarkable. His blood
counts are notable for a WBC of 5,000/ mm3, ANC 500/mm3, hemoglobin of 11.1
g/dl, MCV 100fL, and platelet count of 200,000/ mm3/L. His serum B12 and folate
levels are normal. Prothombin time (PT) is slightly prolonged, but PTT and fibrinogen
are normal. Liver enzyme levels and bilirubin levels are normal. Sweat test for cystic
fibrosis and workup for celiac disease are negative. No intestinal pathology is noted
by upper or lower endoscopy. Mutations in which of the following genes might
account for the constellation of symptoms in this child?
A. c-Mpl
B. ELA2
C. HAX1
D. RPS19
E. SBDS
8. An 18-year-old boy presents with AML. He had severe neutropenia first noted in
infancy and had a history of recurrent bacterial infections and oral aphthous ulcers.
The neutrophil counts rose to normal and the infections resolved after the initiation
of G-CSF. Analysis of the leukemic clone revealed an acquired mutation in the
cytoplasmic domain of the G-CSF receptor. A mutation in which of the following
genes would most likely be present in this patient?
A. c-Mpl
B. ELA2
C. FANCA
D. FLT3
E. RPS19
9. A 19-year-old boy presents with a hemoglobin of 7g/dL, MCV 115fL, WBC of 900/μL,
ANC 10/μL, and platelet count 10,000/mm3. At the age of 5 he had been treated
with ATG and cyclosporine for idiopathic aplastic anemia because he did not have
any siblings. He had a good initial response to immunosuppressive therapy with
normalization of his blood counts, which had been maintained until recently. The
most important next step in management is
A. DNA breakage analysis with DEB/MMC
B. Evaluate bone marrow cytogenetics
C. Flow cytometry for PNH clone size
D. Repeat immunosuppression with ATG and cyclosporine
E. Restart oral cyclosporine only
10. This is your first meeting with a 19-year-old boy who presents with a 5-year history
of mild but stable thrombocytopenia (platelet count ranging between 105–
120,000/mm3). His WBC was 7,000/mm3, ANC of 2,500/ mm3, hemoglobin 13.2 g/dL,
MCV of 110fL, and platelet count of 115,000/mm3. B12 and folate levels are normal.
His father, who does not smoke or drink, developed oral squamous cell carcinoma at
the age of 25. The patient’s exam is notable for leukoplakia. Which of the following
tests are most likely to be helpful in establishing a diagnosis?
A. c-Mpl sequence analysis
B. Mitochondrial DNA sequencing
C. RBM8A genetic testing
D. RPS19 genetic testing
E. Telomere length analysis
11. A 15-month-old boy is referred to you for neutropenia, malabsorption, and severe
acidosis. The bone marrow examination shows vacuolated erythroid precursors and
ringed sideroblasts. Cytogenetics are normal. The most important test to send is
A. Mitochondrial DNA sequencing
B.
C.
D.
E.
MMC/DEB chromosomal breakage study
RPL35A genetic testing
SBDS genetic testing
Telomere length assay
12. A 4-year-old boy is referred for evaluation of macrocytic anemia, neutropenia, and
thrombocytopenia with marrow hypoplasia. On exam, you note short stature, five
café au lait spots, and a scar from surgical correction of a congenital thumb anomaly.
The most important test to send is
A. Erythrocyte adenosine deaminase activity (eADA) level
B. Flow cytometric evaluation of CD55 and CD59
C. Mitochondrial DNA deletion analysis
D. MMC/DEB chromosomal breakage assay
E. NF1 gene mutation analysis
13. You are called to the newborn nursery to see a baby with cutaneous and mucosal
bleeding. The platelet count is 20,000/mm3. The other blood counts are normal.
Labor and delivery were uncomplicated and maternal platelet counts are normal.
The mother was not taking any medications that would affect the platelet count.
There are no signs of infection. On exam, the baby’s arms appear abnormal but
thumbs are present bilaterally. Your differential diagnosis includes the following:
A. Acquired aplastic anemia
B. Amegakaryocytic thrombocytopenia
C. Diamond-Blackfan anemia
D. Shwachman-Diamond syndrome
E. Thrombocytopenia absent radii syndrome (TAR).
14. A 2-year-old girl with a previously normal blood count now presents with a
hemoglobin of 8.5 g/dL, reticulocyte count of 0.1%, and normal MCV, platelets, and
neutrophils. Vital signs and physical exam are normal. Bilirubin, LDH, BUN,
creatinine, and urinalysis are normal. Direct and indirect antiglobulin tests are
negative. Workup for infection, including parvovirus, is negative. She has no
evidence for ongoing blood loss and no occult blood in her stools.Which of the
following is the most appropriate next step?
A. Bone marrow examination
B. eADA level
C. Erythropoietin injection
D. Red blood cell transfusion
E. Serial hemoglobin determinations
15. A patient with Diamond-Blackfan anemia undergoes stem cell transplantation from
his HLA-identical brother. At day 100 neutrophils and platelets are fully
reconstituted, however, the patient remains red cell transfusion dependent. The
marrow reveals red cell aplasia. Genetic analysis reveals 100% donor status. This is
most likely the result of
A.
B.
C.
D.
E.
Anti-red cell antibodies
Donor also having Diamond-Blackfan mutations
Graft-versus-host disease
Inadequate conditioning
Renal insufficiency
Bone Marrow Failure: Answers
Question 1
Answer: B
Explanation: The patient has pancytopenia with macrocytosis and a blunted reticulocyte
count. The marrow is hypocellular for age. This may be due to aplastic anemia, an
inherited bone marrow failure syndrome (IBMFS), or myelodysplastic syndrome (MDS).
Cytogenetics are usually normal in aplastic anemia, while clonal cytogenetic
abnormalities are commonly seen with IBMFS or MDS. Antiplatelet antibody testing
currently is neither sensitive nor specific for the diagnosis of immune thrombocytopenic
purpura (ITP), a diagnosis that would have increased marrow megakaryocytes, not
decreased (as in the vignette). A direct antiglobulin or Coombs test would be positive in
autoimmune hemolytic anemia, a diagnosis that should have an increased reticulocyte
count and increased marrow erythroid cellularity. Although the erythropoietin level
should be elevated in aplastic anemia, it is not diagnostic. Thrombopoietin levels would
not distinguish between aplastic anemia, IBMFS, or MDS. Thus bone marrow
cytogenetics is the most useful test to differentiate the possible diagnoses.
Question 2
Answer: B
Explanation: The treatment of choice for SAA in childhood is an HLA-matched sibling
donor hematopoietic stem cell transplant, which is curative, making HLA typing the next
management step. If no sibling donor is available, immunosuppressive therapy with
antithymocyte globulin (ATG) and cyclosporine is recommended. Blood counts often
remain abnormal, albeit improved to transfusion independence, after ATG and
cyclosporine but there is an ongoing risk of relapse or clonal evolution. Short-term
survival with HLA-matched sibling donor transplant is comparable to that achieved with
immunosuppression. Long-term outcomes are better with an incidence of
posttransplant malignancy lower than that of the emergence of clonal disease (acute
myeloid leukemia [AML], MDS, or paroxysmal nocturnal hemoglobinuria [PNH]) with
immunosuppression. Randomized trials with G-CSF did not show an improvement in
outcome for SAA. Prolonged observation increases the risks of complications such as
allo-sensitization from multiple transfusions, development of infections, or serious
bleeding. Oral androgens are utilized in management of IBMFS such as Fanconi anemia.
Question 3
Answer: E
Explanation: This history of familial anomalies is suggestive of an IBMFS. Idiopathic
pulmonary fibrosis, liver abnormalities including cirrhosis, early gray hair, and
osteopenia, along with dystrophic nails and oral leukoplakia, are all features associated
with dyskeratosis congenita (DC). To date, all of the genes associated with DC involve
either components of telomerase or affect telomere length through the shelterin
complex. The familial pattern here suggests an autosomal-dominant pattern of
inheritance as seen in DC, while Fanconi anemia is autosomal recessive or X-linked and
is associated with congenital anomalies not the later onset finding present in this family.
Telomeres are very short in DC and thus this test is most likely to confirm the clinically
suggested diagnosis. Bone marrow cytogenetics, if abnormal, will guide further
management but cannot establish which IBMFS is present. Increased chromosomal
breakage testing with DEB or MMC would be diagnostic of Fanconi anemia. An elevated
percentage of peripheral blood cells negative by flow cytometry for GPI
(glycosylphosphatidyl inositol) linked cell surface markers would suggest a diagnosis of
PNH, which is unlikely to be familial. Abnormal levels of serum trypsinogen and fecal
elastase would be present in Shwachman–Diamond syndrome.
Question 4
Answer: C
Explanation: Serum sickness is caused by the formation and deposition of immune
complexes and complement fixation in response to the foreign protein. Symptoms
usually develop 5 to11 days following the first dose of ATG. The pattern of distribution
for this rash on the borders of palms and soles is classic. Other symptoms include fever,
myalgias, arthralgias, and joint swelling. Gastrointestinal and neurologic symptoms, as
well as transient renal dysfunction, may also occur. Infectious causes must be promptly
evaluated and ruled out because the patient is very immunocompromised at this stage.
Transfusion-associated graft-versus-host disease may result from the transfusion of
nonirradiated blood products into an immunocompromised host but would present as
profound pancytopenia. Although viral infection or reaction to antibiotics or blood
products are all possible, they do not present with fever and this type of rash.
Question 5
Answer: D
Explanation: A family history of a sibling with aplastic anemia and a cousin with
pediatric AML raises the possibility of an IBMFS even in the absence of other clinical
stigmata such as congenital anomalies. The significant transplant-related toxicity
experienced by the sibling is suggestive of an IBMFS such as Fanconi anemia. A reducedintensity transplant conditioning regimen would be indicated for a patient with Fanconi
anemia. Peripheral blood tests for Fanconi anemia may be negative if the lymphocytes
have reverted to wild type (somatic mosaicism). The gold standard to establish the
diagnosis of or conclusively exclude Fanconi anemia in this situation is to test skin
fibroblasts. There is no advantage to testing the bone marrow aspirate for chromosomal
breakage because somatic mosaicism also has been reported in the hematopoietic cells
and chromosomal breakage assays have not been standardized for marrow samples.
Patients with Fanconi anemia typically fail to respond to ATG and cyclosporine therapy
for aplastic anemia. Oxymethalone is commonly used to support blood counts in
Fanconi anemia patients but should not be considered until a diagnosis is confirmed and
transplant options considered.
Question 6
Answer: E
Explanation: Cytopenias, particularly anemia, improve with oxymetholone therapy in
more than 50% of Fanconi anemia (FA) patients. Although liver adenomas may develop
spontaneously in FA patients, the risk of developing a liver adenoma, peliosis hepatis—
literally blood lakes—or liver tumors is increased with oxymetholone. Regular screening
with liver function tests and hepatic ultrasounds to monitor for toxicity are
recommended for FA patients receiving oxymetholone. Androgen-associated liver
adenomas may resolve after androgens are discontinued, but some may persist even
years after androgens are stopped. Although neutropenia in FA patients may respond to
treatment with G-CSF or GM-CSF, neither of these treatments is associated with an
increased risk of liver adenomas. Erythropoietin generally is reserved for FA patients
who have low erythropoietin levels. Danazol is an alternative to oxymethalone therapy
that may be used in female patients to minimize the virilization observed with
oxymethalone.
Question 7
Answer: E
Explanation: Failure to thrive, steatorrhea, and the elevated PT suggestive of vitamin K
deficiency are consistent with fat malabsorption. The combination of exocrine
pancreatic insufficiency and otherwise idiopathic neutropenia are diagnostic of
Shwachman-Diamond syndrome, which is associated with mutations in the SBDS gene in
the vast majority of cases. Mutations in c-Mpl are associated with congenital
amegakaryocytic thrombocytopenia and clinical thrombocytopenia. ELA2 mutations are
associated with severe congenital neutropenia (SCN) or cyclic neutropenia (CN). HAX1
mutations also are associated with SCN. Exocrine pancreatic insufficiency is not
characteristic of either SCN or CN. RPS19 mutations are associated with DiamondBlackfan anemia, which is characterized by red cell aplasia.
Question 8
Answer: B
Explanation: The vignette describes a typical case of severe congenital neutropenia.
ELA2 mutations are associated with SCN or CN. Mutations in the G-CSF receptor
frequently arise in patients with severe congenital neutropenia and result in constitutive
activation of the G-CSF receptor. The clinical significance of these mutations is not clear
because some mutant G-CSF clones progress to leukemia while others remain stable for
many years. However, development of AML after prolonged GCSF therapy is a
commonly observed event in patients with SCN. RPS19 mutations are associated with
Diamond-Blackfan anemia. C-Mpl mutations are associated with congenital
amegakaryocytic thrombocytopenia. FANCA mutations are present in Fanconi anemia
group A. FLT3 is the most commonly mutated gene in AML. None of the other mutations
are associated with the clinical history of preceeding neutropenia.
Question 9
Answer: B
Explanation: Relapse of aplastic anemia following treatment with ATG and cyclosporine
is common (up to 30% in some series). Patients treated with immunosuppressive
therapy with ATG and cyclosporine are at increased risk for developing clonal
cytogenetic abnormalities, including monosomy 7, as well as leukemic transformation.
Thus, a bone marrow aspirate and biopsy with cytogenetics would be the next step to
evaluate the etiology of his pancytopenia to guide treatment decisions. If morphologic
evidence of myelodysplastic syndrome, cytogenetic abnormalities, or leukemia is
present, therapy with include stem cell transplantation if an unrelated donor could be
found. Although re-evaluation at relapse should include reassessment of the size of the
population of GPI-deficient cells (“PNH clone”) this is not the most important test to be
evaluated. DEB or MMC testing for DNA breakage should have been done with the first
presentation, and a patient with Fanconi anemia or another breakage syndrome would
have been unlikely to respond to immunosuppressive therapy and maintained normal
counts for more than a decade. Patients who experience a relapse of their aplastic
anemia soon after immunosuppression is withdrawn may be treated with cyclosporine
alone or with combined therapy. However, the most important diagnostic evaluation is
to re-examine the bone marrow with morphology and cytogenetics to rule out the
acquisition of premalignant changes.
Question 10
Answer: E
Explanation: Longstanding cytopenias with macrocytosis are frequent features of
IBMFS. Leukoplakia with an increased risk of squamous cell carcinoma is associated with
DC. The family history is consistent with an autosomal dominant pattern of inheritance.
The inheritance patterns of DC vary, depending on the gene, and may follow autosomal
dominant, autosomal recessive, and X-linked modes. Telomeres will be very short in
multiple hematopoietic cell lineages in DC. Fanconi anemia is associated with increased
risk of squamous cell carcinoma but is a recessive genetic disorder. In patients with both
of these syndromes, suspicious oral lesions should be biopsied promptly. c-Mpl
mutations are associated with congenital amegakaryocytic thrombocytopenia, RPS19
mutations with Diamond-Blackfan anemia, RBM8A mutations with thrombocytopenia
and absent radius (TAR) syndrome, and mitochondrial DNA deletions with Pearson
Syndrome. None of these other syndromes are associated with an increased risk of
leukoplakia or squamous cell carcinomas.
Question 11
Answer: A
Explanation: These are the classical morphologic finding in the bone marrow of patients
with Pearson syndrome resulting from a mitochondrial DNA deletion. ShwachmanDiamond syndrome is caused by mutations in the SBDS gene. Although ShwachmanDiamond syndrome and Pearson syndrome both present with marrow failure and
exocrine pancreatic dysfunction, Shwachman-Diamond syndrome lacks the vacuolated
erythroid precursors. An MMC/DEB chromosomal breakage study is the diagnostic test
for Fanconi anemia. RPL35A mutations are associated with Diamond-Blackfan anemia.
Very short telomere lengths are associated with DC.
Question 12
Answer: D
Explanation: This is a classic presentation of Fanconi anemia, which is associated with
increased chromosomal breakage in response to mitomycin C (MMC) or di-epoxy
butane (DEB). Elevated eADA levels are seen with Diamond-Blackfan anemia, which
typically presents with macrocytic pure red cell aplasia. An increased proportion of cells
missing CD55/CD59 are seen with paroxysmal nocturnal hemoglobinuria. Mitochondrial
DNA deletions are associated with Pearson syndrome. Café au lait spots are seen in
neurofibromatosis, but marrow failure and thumb abnormalities are not typical of this
disorder.
Question 13
Answer: E
Explanation: Both Fanconi anemia and thrombocytopenia absent radii (TAR) are
autosomal recessive disorders that may present with radial anomalies and low platelets
in infancy. In TAR the defect is intercalary with missing radii and normal thumbs. In FA
the defect is terminal; if the patient has an absent radii the thumbs are also abnormal or
missing. Amegakaryocytic thrombocytopenia may present with thrombocytopenia early,
but not absent radii or thumb anomalies. Shwachman-Diamond syndrome may present
with cytopenias early in life but radial ray anomalies have not been commonly reported.
Diamond-Blackfan anemia presents with red cell aplasia and present radii although the
thumbs may be digitalized (look like a finger). Acquired aplastic anemia is not typically
associated with congenital anomalies.
Question 14
Answer: E
Explanation: This is a classic presentation of transient erythroblastopenia of childhood
(TEC) in which a previously healthy child suddenly develops a moderate to severe
hypoplastic anemia. Therapy is supportive with transfusion for severe cases. In rare
instances TEC may be associated with neutropenia and thrombocytopenia as well, which
also resolve spontaneously. A similar scenario may be observed during the aplastic crisis
of a hereditary hemolytic anemia, except in that case there should be a prior history of
hemolysis. In this case, the child is clinically stable with no physical or laboratory
evidence of malignancy to recommend a bone marrow examination, neither is there
evidence of decompensation to require transfusion. Diamond-Blackfan anemia, which is
often associated with an elevated eADA level, typically presents in infancy or before age
2 with macrocytic anemia. TEC typically presents at an older age than Diamond-Blackfan
anemia and the MCV typically is normal. Erythropoietin levels typically are already high
with red cell aplasia.
Question 15
Answer: B
Explanation: In matched sibling donor transplants for IBMFS it is essential to critically
evaluate the donor for evidence of the same IBMFS. Differences in clinical expression of
these disorders require that the donor be genetically tested for the mutation in the
recipient (if known). In Diamond-Blackfan anemia evaluation of an eADA also may be
helpful because mutations are only known for approximately 60% of clinically diagnosed
patients. In the vignette, the donor also had Diamond-Blackfan anemia, which was not
apparent to the transplant team leading to red cell failure to engraft in the recipient.